Shears



Sept. l, y1925.

M. A. JACKSON SHEARS 2 Sheets-5heet 1 Filed Sept. EOy 1924 Sept. 1, |925. I 1,552,165

M. A. JACKSON SHEARS Filed Sept. `30, 1924 2 SheetrShoena u N N lmlh Mali Jazolt @Maw Wam? Patented Sept. l, 1925.

PATENT OFFICE?.

MARK A. JACKSON, OF CO'LLINGSWOOD, NEW JERSEY.

SHEARS.

Application filed September 30, 1924. Serial No. 740,721.

To all whom t may concern.:

Be it known that I, MARK A. Jackson, a citizenof the United States, residing at Collingswood, in the county of lCamden and State of New Jersey, have invented certain new and useful Improvements in Shears, of which the following is a specification.

My invention relates to shears Vfor cutting slate asbestos or other brittle sheet material.

The objects are to provide shears with which slate and asbestos or other brittle sheet material, may be quickly and accurately cut without cracking or breaking the same; which includes a blade so constructed that it may be changed, end for end, when one end isworn; which will have an extension for supporting al cut part of the sheet material, and which may be attached to either side of the shears for use by a right or left handed operator.

These objects, and other advantageous ends which will be described hereinafter, I attain in the following manner, reference being had to the accompanying drawings, in which- A Figure 1 is a side elevation of shears constructed in accordance with my invention,

Figure 2 a plan view of the shears shown in Figure 1,

Figure 3 an enlarged section taken on line 3-3 of Figure 1, and

Figure 4 an enlarged section taken on line 4 4 of Figure 1.

Referring to the drawings, 1 indicates a frame having a slot 2, 3 a pair of shearing blades secured within the slot, 4 a main shearing blade pivoted to the frame, 5 a detachable handle on the blade and 6 a frame extension which may be detachably secured to either side of the frame.

Frame 1 consists of a pair of frame members 7 and 8 having spacers 9 therebetween and a bolt 10 passing throughv the frame members and each spacer.

The shearing blades 3 are preferably made from steel strips and secured to the adjacent sides 11 of the frame members by bolts 12 having countersunk heads. The ends of the shearing blades 3 preferably have the upper spacer 9 therebetween to insure accurate spacing.

The main blade 4 is preferably made from a steel strip and has a shank 13 of a less thickness than the shearing edges 13a. This shank is of uniform thickness from the top edge 14 to a point 15 near the shearing edges. From this point 15 the shank increase-s in thickness to shearing edges 13a atl opposite sides of the blade. A shallow V- shaped groove 16 is preferably cut in the bottom edge of the blade between the shearing edges 13a. Eachend of the blade is provided with suitable apertures 17 and 18 for detachably securing handley 5 thereto and for pivoting the blade to the frame. As shown, one end of blade 4 is pivoted on the upper spacer 9, they spacer passing through aperture 18. has the detachable handle 5 secured thereto by a pair of bolts 19 passing through apertures 17 and 18.

The frame extension 6 consists of a plate 20 having clips 21 secured thereto which Y. may be detachably secured to either of the frame members 7 and 8.' As shown, these clips are secured to fra-me member 8 by the bolts 12 for use by a right handed operator,

and may be likewise secured to the frame member 7 for use by a left handed operator.

To cut brittle sheet material, such as slate or asbestos shingles, the shingle is placed on the top of frame 1 under the main blade 4 as shown at 22. The blade is then swung on its pivot by moving handle 5 downward so that the shearing edges 13a will shear a slit in the shingle as shown at 23. The shearing is yeffected by each of the edges 13a at opposite sides of the blade and the upper edges of the shearing blades 3. Blade 4 is swung downward as far as possible by the operator, the distance depending on the force applied to the handle. The usual distance is substantially as shown in Figure 1. After a short slit, as shown in Figures 1 and 3, is cut in the shingle by the lirst swing of blade 4, theblade is raised and the shingle slid along and under the blade as far asypossible. The shingle may be easily slid along under the blade, because the shank, being of reduced thickness, avoids binding with the sides of the slit. The only parts of the bla'de engaging the sides of the slit, are the shearing edges 13a. They allow free sliding movement of the shingle along the blade even if the shingle be unavoidably shifted to one side by the operator during the sliding. The main blade 4 is then moved downward as before until the shingle is cut in two. One cut The other end o-f the bladev part of the shingle is held by the operator and the other cut part is supported by frame member 8 and extension 6.

When the blade is worn and the shearing edges are dull, it may be changed, end for end, by removing bolts 19 from ythe .handley and the bolt l which forms the pivot. The apertures in each end of the blade, being similar, will accurately lit the pivot and the handle when the blade is changed.

When a righthanded operator is using the shears, extension 6 is attachedfas shown in the drawings. When a left handed operator isusing; the shears, extension 6 is attached tothe other side of the frame by detaching the clips 2l from the bolts l2 on oneside of 291 described,brittlesheetmaterial may be easilyy theiirame, and attaching them to the bolts 12 on the other side ofthe frame.

It will be seen that with the shears above andvr quickly cut without-breaking because. a slight unavoidable side shifting of the niaterial as, itV isgmoved; under the main blade will not cause the sidesof the slit tofbind vagainst the sides. of the shank, and the cut.

part. of the; material7 which is not held by the operator, will be supportediby the frame extension.: Either end` of the blade may be pivotedtoy either end of the frame, thus insuringflong 'li-fezof the blades.

While vI have described my invention as .taking 4auparticular form, it willbe understood.thatthevariousparts may be changed without departing fromthe spirit thereof, andhence I do not limit myself to the preciseiconstruction.set fortlnbut consider that `Ii amiat liberty to make such changes and alterations, as fairly come within thev scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is l. Shears including a framehaving a slot; a shearing blade secured to each side of the slot; a main blade .having a shank of less thickness than the shearing edge, pivoted to *the trame and adapted to swing between the shearing blades, and a detachable handle adapted te be -secured to either end of the main blade, the shank being of uniform thickness from the top edge to a point near the shearing edge andl increasing in thickness from said peint to the shearing edge, the

lmain blade having apertures at each end for pivoted to the frame members and adaptedlte swing between the shearing blades; a frame extension adapted to be secured to either frame member, and common means for securing al shearing blade and the-extension to either side ofV1 theA `frame.

In testimony whereof I 'have signed my name to this specification.

MARK A. JACKSGN; 

